Toldge

No hole for the o2 sensor, i've read that other people had someone drill a bung o2 receptacle into the new hi flow cat. Is this necessary, or can i just leave the o2 sensor unplugged and maybe ziptie it to something on the undercarrage to keep it secure. Will my engine run lean or is the rear o2 sensor for emissions only?

96 accord ex manual

AccordMD

i got a 96 lx not sure if i needed the o2 sensor but i didn't want to drill a hole in my chrome high flow cat so i just zipped it up and under out of the way i haven't had a problem yet that was cause by it

P_Adams

The 2nd O2 sensor is required for proper OBD-2 operations, and emissions on your year car; so you'll have to make some provisions for mounting it.
One of several options you might want to take would be to weld the O2 mounting bung to the intermediate pipe which follows the Catalytic Converter, that way you won't damage your new Converter. Either the Converter pipe or the intermediate pipe will work.
If you can't find a supply for the bung, I've used 19mm spark plug anti-foulers in their place. Just drill out the bottom to accomodate the O2 probe and weld the adapter to the pipe.

P

fw190bvi

if teh o2 sensor isnt allowed to be exposted to exhaust gas air, i believe itll make the car think its running WAAAAAAAAAAAAAAAAY too lean

ATX96coupe

yeah, the O2 sensor is very important for your car, because when your fuel system switches over to closed loop, it takes the reading off the O2 sensor to regulate the amount of fuel needed. just get a couple of O2 bungs and have a muffler shop or someone weld it on for you.

Mark

AFAccord

I don't mean to pop any balloons around here, but if your "high flow cat" doesn't already have a hole for the second O2 sensor, chances are it probably doesn't have a catalyst, which means that it's not a catalytic converter at all. For those of you on ebay, congrats on your new resonator...

Now if your "high flow cat" doesn't have a hole for the O2 sensor, but DOES have a catalyst inside (the honey-comb center that nearly prohibits you from seeing through it) then it could just be a universal fit, but that's highly unlikely, being a performance part.

Either way, if it is in fact a true cat, you MUST install the second O2 sensor behind it. (ie. drilling your own hole, welding a nut over the hole, and screw it in) If you are trying to get away with and ebay "high flow chrome cat" a.k.a. Resonator, you might as well not even install the 2nd sensor. As said before, if you don't use an actual converter and/ore the second sensor, your mixture will be extremely erratic, eventually screwing all your exhaust sensors, and reducing your performance to that of a kid running in the special olympics. If nothing has screwed up yet, don't worry, it will catch up. Its the nature of ODB-II emissions systems. Just a heads up. I'm only preaching cause i've seen it done, and it's not pretty.